Objects A and B have the same mass of 3.4 kg and are at their melting points. They melt when 4.9 × 104 J of heat is added to A and when 11 × 104 J is added to B. (a), (b) Determine the latent heat of fusion for the substance from which each object is made. (c) Find the heat required to melt object A when its mass is 6.8 kg.